About the blog: What Things Are Made Of


The United States relies on imports for dozens of commodities in everyday use. Often enough, that reliance is 100%. In this book I aim to provide awareness of the hidden geology and mineralogy behind common things, and to develop an appreciation for the global resource distribution that underpins our society. While concerns about oil import reliance are in the news every day, our needs for other minerals are comparable and are typically unknown even to technologically aware Americans.

Saturday, December 26, 2009

Accidental disoveries

As a scientist, I appreciate the role of serendipity in discovery, whether in finding an oil field or uncovering the properties of strange compounds and elements. One of the most enjoyable aspects of writing What Things Are Made Of was learning about some of the interconnections that led to unexpected modern uses for chemicals.

The element selenium’s photoelectric properties were discovered accidentally by a researcher attempting to improve the electrical conductivity of undersea cables. Englishman Willoughby Smith worked for the Gutta Percha Company—named for the natural rubbery substance used to coat cables—and oversaw cable laying across oceans from the Mediterranean to the North Atlantic. Shortly after working on the first cable connection from Java to Darwin, Australia, Smith moved from management to his first love, technical engineering problems. Testing selenium showed it to have erratic properties, unsuitable for his needs. But Smith’s curiosity led to a critical discovery in 1873.

Quote from the book:

Not one to simply cast the selenium aside, Willoughby Smith investigated further – and discovered that the metal’s electrical resistance was proportional to the strength of light falling on a selenium bar.

Selenium is usually a byproduct of copper refining. Consequently, Belgium, with major refining facilities, is the primary source of selenium imports to the U.S., and imports accounted for a third or more of our consumption in the late 1990s (recent figures are not available because there is only one domestic producer, and the data are withheld to avoid disclosing proprietary company information).

Selenium decolorizes glass, gives ruby-red color to plastics, coats photocopier drums, works in electric-eye doors, is a livestock feed supplement, and helps solar cells and anti-dandruff shampoos do their jobs.


EcoRover said...

Dick, I love the stories of accidental discovery (and near discovery) in the history of science. Montana Tech's very own C.H.Clapp and his near discovery of Krypton, I think it was. Also interesting is the question, can you discover something if you don't have a name for it or understand what it is? Cf. Lavoisier's "oxygen" vs. Priestley's "vital air."

Richard Gibson said...

Pat, I'm not sure about discovering things you don't understand, but the Manhattan Project's scientists knew what they were after when they had working names for undiscovered elements - pandemonium and delirium, which eventually became americium and curium.